Process of treating slags.



L B. HERRESHGF, IIi PROCESS 0F TREATING SLGS.. APPLICATION FILED APILQ,ISIS.

9&3 i 3,3%?) @aI-@Died June 26, i917.

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Specification of Letters Patent. fmlgymtgrgggum@ 205,39 jig,

Application filed pril 9, 1915. Serial No? mitlg.v

To all whom 15' 'may concern:

Be 1t known that I, JAMES BROWN HER RnsHoFF, J r., a citizen of theUnited States,

and a resident of the borough of Queens,

city and State of New York, have invented i a certain new and usefulProcess of Treat ing Slags, of which the following is a specin cation. 1

ll/ly invention relates to thetreatment oi metallurgical slags whichhave associated therewith'either chemically or mechanically a proportionof the metal ingredients of the molten m'ass from which the slag wasproduced or with which it was last in contact and from which it has beenremoved. The ob] ect of my lnventlon lsto recover m whole or 1n partfrom these slags associated or con tained metallic ingredients obtainedfrom the molten mass, the invention having especially importantapplicatie in `such cases in which the slag carries with it relativelyvery valuable metallic ingredients.

My new process consists, broadly stated, in mixing, by which I includewashing1 or otherwise bringing into intimate contact, a molten slagcontaining such metal ingredients desired to be recovered and a moltenmaterial consistingof metals or metal compounds or mixtures thereof,which contains a smaller'percentage of such metal ingrefn ents than themolten mass from which ti slag has been removed, this deiinition bein-g;meant to include, of course, a molten material which is wholly free fromsaid ingredients.

The removal of the metal values. from the 'slag in this way may bewholly a mechanical action, but in some cases the molten material may beselected so as to react chemically with the metal values, or some ofthem, 4which are-contained in the slag and in such cases the action willbe either wholly chemical or partly mechanical and partly chemical.

The molten' material may be produced in any suitable way. vFor example,it may be' produced partly or wholly by treating the .molten slag withreducing agents, such as reducinggases or it may be obtained byysmelting opera-tions. The.. mixing of the slag and the molten materialmay also be accomplished in any suitable manner. The

slag may,`for'-instance, be caused to fall-1" 20% matte therein and. Aits` contained copper;

upon the surface of and thuspenetrate'into the molten material in asuitable container,

or' these substances maybe agitated as ,in a

tangled with the rotary mechanical device' or by stirrers or mixing maybeproducedby passing gases through these substances, or causing the subvstances to tlo'w together through a long trough. f t

In order to illustrate my Vinvention fully and completely, lwill'nowdescribe it 'more specifically and particularly, as'applied tothe metallurgy of copper and in doing so reference will be made to theaccompanying drawing which-'shows schematically an arrangement ofapparatus by the use of which the process may be carried out. Copperslags, thatis slags obtained from converters or from reverberatory orsmelting furnaces are principally silicates of iron, lbut they all haveassociated therewith copper values and in most cases they also carrygold and sil-y `ver. `Copper smelter slag, for. example,

which is principallyan iron silicate, contains besides smalliquantltiesci' gold and silver, copper in the form of copper silicate,

and of copper matte mechanically enmatte produced bythe smelter, Ingeneral the percentage of copper contained in the' slag is about 1% ofthe percentage of copper in the matte produced by the smelter. If thesmelter is so operated and conditions are so maintained that a mattecontaining of copper reduced, the percentage .of copper in the .sla-g isabout .6% lwith a 40% matte the slag loss is about .4% copper.

.llmploynng the apparatus.illustrated, the sinelter slag produced by thesmelting furnace l, which also produces, say, 60% matte is run into aseria' of settling tanks 2, 3,'

4: and 5. The tank will contain the 60% 'tank fl, 10% matte and tanlr,8% matte.

The slag and matte from the furnace l dis chargesinto the 'tar l and theslag sepa rates out on top; tur; slap; overflows and drops into thetanlr 3 mixes with.the

after .part of the con tained copper, and with it, cconrsey'cld ironsilicate and dissolved therein. The amount ci' such lngredientsI dependsof course upon the grade of the' nus loses apart of and silver, isrecovered iu this manner in tank il, thc slag` in its then conditionoverflows into tank Ll and because oi the still lower grade of matte intank t a further removal of copper :troni the slag is eli'ected. lnlilremanncra Jurtlmr removal is eilected in tank' 5 and also in the longtrough 6 down which, together with the purilied slag, a still. lowergrade ot matte, say 5%, is run lhis matte may be supplied by thesmelting furnace 9. From the trough (l, the slag and matte dischargelinto the rotary mixer 7. '.l`l1e mixer may be ol any suitableconstruction, preferably being` provided, like the tanlis and troughwith a refractory lining, and may be rotated in any suitable manner.From the mixer 7 the slag and matte llow into the settling tank 8, fromVwhich the slag and matte may be drawn oit separately.rv The process maybe conducted wholly or partly continuously or intermitteiitly'.

wThe loiv grade matte may be mixed sutilciently with the slag in one ormore of the tanks 3, 4f and 5 and the resulting slag may be suliicicntlyfree from copper for all practical purposes. Or the long trough 6 mayaccomplish the desired removal of contained copper Without the tanks andthe rotary mixer or a part ot these elements. 0r the mixer 7 may be usedwithout the other elements.

rlhe tanks, trough, mixer and settling tank may be heated, as by thecombustion of coal, charcoal or cil, so as to maintain the contents inliquid condition and preferably also so as to maintain a neutral orreducing atmosphere in Contact with the materials being trib-ated.

the settling tank 8 will contain about 1% of the percentage of copper inthe settling tank .matte in accordance with the general rule expressedabove. Accordingly, if a treating matte has been employi-zd in the mixer7, the copper in the slag will be about .05% although before treatmentit contained .6% copper. The saving oi" .55% copper, and equivalentamounts of gold and silver, thus effected, makes the process veryvaluable commen icially. The process is capable of effecting importanteconomies also in the production of thematte, or other material fromwhich the original slag wasobtained. For example, the copper blastfurnaces or reverberat-ory iurnaces or converters can advantageously berun with richer regali and more silicious slags so that both the cost offluxl and of converting will be reduced. The

another tank and there mixed with a still lower grade vot' matte, andthen allowed to settle out and this process may be continuedindefinitely, using in each case a lower grade ci? matte, untilpractically all of the metal values of the original slag have been v ingoperation is gradually enriched in copper. and measurably also in goldand silver, and'after a time should be replaced by matte of a lowergrade; this may be accomplished by transferring the matte of eachreceptacle to the receptacle immediately before it in the treatingseries.

The above process as set forth in connec-- tion with coppermetallurgy,.can readily be applied advantageously to the metallurgy.oflother metals, such as gold, silver, tin, lea'd,

nickel and cobalt. Ingold or silver metal-v lurg metallic lead may beused as the molten material correspondmg with the loW grade matte usedin the copper process described above. In tin metallurgy a slag cornnposed mainly of iron or calcium silicate, but containing tin silicate,is produced; Withsuch a slag a molten material such as molten pig ironwould preferably be employed, in which case iron, free or in combinationWith tin, will react with the vtin silicate of the slag with theproduction of tin which Would dissolve in the iron and iron silicatewhich goes into the slag. In lead metallurgy, the smelting process Wouldpreferably be conducted with excessive amounts of lead silicate in theslag so as to produce a purer lead bullion than is obtained in theordinary and usual processes wherein the slag loss must be kept as lowas ossible. The high metal values in the slag, 1n the shape of thisexcessive lead silicate, can readily be recovered by my process inwhichloW grade lead 'matte would preferably be used as'molten material. A l

l claim: l

l. The process of recovering the metallic content from metallurgicalslags, Which comprises agitating the slag with a molten materialcontaining a different percentage of metallic content than said slag.

2. The process of recovering the metallic content from metallurgicalslags, which com prises agitating the'slag With a molten materialcontaining a smaller percentage of metallic content than said slag.

3. The process of, recovering from metallurgical slags a containedmetallic ingredient los 'neeneee washing the molten slag with a moltenmaterial. containing a smaller percentage of such ingredient than'thesaid molten mass, substantially as and for the purpose described.

4. The process of recovering from metallurgical slags a containedmetallic ingredient of the'molten mass from which the slag has beenremoved, which comprisesmeclhanically Washing the molten slag Withaseries of baths of molten material containing a' smaller percentage ofsuch ingredient than the said molten mass, and each bath of the seriescontaining a smaller percentage of suoli ingredient than the bathimmediately preceding-in the series, substantially as and for thepurpose described. v I

5. The processif recovering from copper metallurgical slags copper,contained therein, of the copper matte from which the slag has beenremoved, which comprises mechanically-Washing tliemolten slag With acopper matte containing a smaller. percentage of copper than said firstmentioned copper matte, substantially as and for the purpose described.l

6. The process of recovering from copper metallurgical slags copper,contained therein, of the copper matte from which the slag has beenremoved, which comprises mechanically Washing the molten slag with aseries of baths of copper matte containing a smaller percentage ofcopper than said first mentioned copper matte, each bath of the seriescontaining a smaller percentage of copper than the bath immediatelypreceding in the series, substantially as and for the v purposedescribed. V

7. The process of recovering froinmetallurgical VSlags a metallicingredient of the molten mass from which slag has been removed, whichcomprises projecting molten slag into a molten material containing adifferent percentage of such ingredient than the said molten mass,substantially as and for the purpose described.

In testimony whereof, l have hereunto set my hand in the presence oi'two subscribing Witnesses.

' JAMES BROWN HEERE-SHOFF, JR. Witnessesz JOHN A, FnReUsoN, FRITZZIEGLER, J r.

